Making a Fullscreen Background Image

Hello,

I Making presentation in flash publish as .exe

Document size is 1024x768

i using this code for fullscreen

fscommand("fullscreen", "true");

but my background img size is 1024x500,

so when i publish the movie, top & bottom area is color fill by document bg color

i want background fill by bg img

how can i do that????

Please Help!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks

Mandar